Brain MRI follow‐up of patients with persistent isolated optic neuritis

In this study a brain MRI long‐term follow‐up of 19 patients at presentation with Acute Isolated Optic Neuritis (AION), who did not develop further neurological disturbances, was performed to evaluate the frequency of subclinical evolution of the pathological process. At presentation, the brain MRI in nine patients was abnormal and in 10 normal. CSF oligoclonal bands were found in 11 patients, five of whom had normal basal MRI. All patients with abnormal basal MRI had new lesions on follow‐up scans, while only one of the patients with a normal basal brain MRI had multiple lesions on the second scan. Our data suggest that about 50% of patients with AION had subclinical activity, even though there were no new clinical relapses.